Long-term follow-up of Ru-106/Rh-106 brachytherapy for posterior uveal melanoma

High- compared with low-dose radiosurgery for uveal melanomas

Object. The authors compared the results of gamma knife radiosurgery in patients with uveal melanoma who underwent high-dose (treated from 1992–1995) and low-dose irradiation (treated from 1996–2002).

Methods. Thirty-one patients with uveal melanomas were treated with a mean margin dose of 52.1 Gy (high dose) and 33 with a mean dose of 41.5 Gy (low dose), and results were compared between groups. The technical procedure was the same in each group except for radiation dose.

In the low-dose group, complete tumor regression (scar formation) occurred in 12% and in the high-dose group in 26%. Partial regression (reduction of the tumor prominence between 50 and 80%) occurred in 81% of the low-dose group and in 58% of the high-dose group.

Neovascular glaucoma as a severe complication developed in 9% of the low-dose group and in 48% of the high-dose group.

Conclusions. Reduction of the margin dose from 52.1 to 41.5 Gy appears to achieve the same rate of tumor regression but is associated with a lower rate of severe side effects such as neovascular glaucoma. The follow-up period in the lowdose group, however, was much shorter.

Rhegmatogenous retinal detachment after transscleral local resection of choroidal melanoma

OBJECTIVE

To report on the incidence and outcome of rhegmatogenous retinal detachment after transscleral local resection of choroidal melanoma.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

One hundred fifty-six patients with choroidal melanoma treated by transscleral local resection between January 1993 and June 2000.

INTERVENTION

Transscleral choroidectomy or cyclochoroidectomy for uveal melanoma, with ocular decompression by single-port pars plana vitrectomy and, in most patients, adjunctive ruthenium plaque radiotherapy.

MAIN OUTCOME MEASURES

Incidence of rhegmatogenous retinal detachment according to predictive factors and outcomes reported in terms of anatomic success, visual acuity, and ocular conservation.

RESULTS

Rhegmatogenous retinal detachment occurred in 28 (18%) eyes and was significantly more common in patients with thick tumors (Cox univariate analysis, P = 0.001) and in males (Cox univariate analysis, P = 0.013), with posterior tumor extension being of borderline significance (Cox univariate analysis, P = 0.069). Surgical treatment of the retinal detachment was performed in 25 patients; it was undertaken at our center in 22 patients and at the referring hospital in 3 patients. Anatomic success was achieved in 21 (84%) of these 25 patients, with 7 eyes retaining counting fingers vision, and 3 eyes seeing 6/60 or better. Ten eyes treated for retinal detachment were enucleated because of recurrent tumor (four eyes), retinal detachment (three eyes), wound dehiscence (one eye), phthisis (one eye), and poor visual acuity (one eye). Eleven eyes known to have a retinal tear underwent prophylactic vitreoretinal surgery at the end of the local resection, with only one (9%) of these subsequently developing retinal detachment.

CONCLUSIONS

Rhegmatogenous retinal detachment after transscleral choroidectomy or cyclochoroidectomy for uveal melanoma is a serious complication requiring early vitreoretinal surgery.

Late radiation failures after iodine 125 brachytherapy for uveal melanoma compared with charged-particle (proton or helium ion) therapy

OBJECTIVE

To evaluate late (more than 5 years) radiation failures after uveal melanoma treatment.

DESIGN

Comparison of three retrospective, interventional, partially randomized case series.

PARTICIPANTS

Nine hundred ninety-six patients who were treated in several phase I, II, and III trials of uveal melanoma radiation.

MAIN OUTCOME MEASURES

Follow-up period, treatment history, recurrence rates, type of recurrence, and mortality associated with late local recurrences.

RESULTS

Eleven of 996 irradiated uveal melanoma patients experienced intraocular recurrence more than 5 years after radiation. All 11 of these patients were treated with iodine 125 ((125)I) brachytherapy. Late recurrences were detected between 5.5 to 15.3 years after treatment. These patients did not have either high-risk clinical parameters (thin, posterior tumors in proximity to the optic nerve) or radiation dosimetry characteristics (low dose-delivery radiation) associated with a known increased risk for tumor recurrence after radioactive plaques. The annualized incidence rate for regrowth was 1.9% per year between 5 and 15 years after (125)I brachytherapy. In contrast to charged particles, the risk of late recurrence after (125)I brachytherapy continued with increased follow-up.

CONCLUSIONS

There was a significantly higher late recurrence rate with (125)I brachytherapy as compared with charged particle radiation. Although tumor enlargement 5 or more years after radiation can be the result of intratumor hemorrhage, in a patient treated with radioactive plaque, a late failure is a distinct possibility.

Plaque radiotherapy for large posterior uveal melanomas (> or =8-mm thick) in 354 consecutive patients

OBJECTIVE

To assess treatment complications and tumor control after plaque radiotherapy for large posterior uveal melanomas measuring 8 mm or greater in thickness.

DESIGN

Prospective noncomparative interventional case series.

PARTICIPANTS

Three hundred fifty-four patients each of whom had a posterior uveal melanoma measuring 8 mm or greater in thickness treated with plaque radiotherapy.

MAIN OUTCOME MEASURES

The four endpoints included (1) poor final visual acuity (20/200 or worse), (2) enucleation, (3) local tumor recurrence, and (4) metastasis. The clinical data regarding patient features, tumor features, and radiation parameters were analyzed for their impact on the four main outcomes using Cox proportional hazards regression models.

RESULTS

Using Kaplan-Meier estimates, final visual acuity was poor in 57% at 5 years and 89% at 10 years follow-up. Using multivariate analysis, the most important risk factors for poor visual acuity included retinal invasion by melanoma, increasing patient age, iodine 125 (I(125)) isotope, and <2 mm distance to the optic disc. Treatment-related complications at 5 years included proliferative retinopathy (25%), maculopathy (24%), papillopathy (22%), cataract (66%), neovascular glaucoma (21%), vitreous hemorrhage (23%), and scleral necrosis (7%). Enucleation was necessary in 24% at 5 years and 34% at 10 years follow-up. Using multivariate analysis, the risk factors for enucleation included left eye, peripheral tumor margin anterior rather than posterior to the equator, increasing tumor thickness, and ruthenium 106 (Ru(106)) isotope. Using Kaplan-Meier estimates, local tumor recurrence was found in 9% at 5 years and 13% at 10 years follow-up. Using multivariate analysis, risk factors for tumor recurrence included Ru(106) radioisotope and ciliary body involvement with tumor. Tumor-related metastases were found in 30% at 5 years and 55% at 10 years follow-up. Using multivariate analysis, risk factors for metastases included inferotemporal meridian, anterior extension of the tumor to the iris root, increasing tumor base, and posterior margin < 2 mm from the optic nerve.

CONCLUSIONS

Plaque radiotherapy provided tumor control at 10 years in 87% of patients with selected large posterior uveal melanomas (>8 mm thick) that otherwise would have been managed with enucleation. The large intraocular mass and associated features and radiation complications led to poor visual acuity in most patients. At 10 years follow-up, enucleation was necessary in 34% of patients, and metastasis developed in 55% of patients.

Rhodium and its compounds as potential agents in cancer treatment

The antitumor activity of the inorganic complex cis-diammine-dichloroplatinum(II) (cisplatin) led to the development of other types of non-organic cytostatic drugs. Numerous platinum other platinum and non-platinum metal compounds were shown to be effective against animal model tumors as well as tumors in man. However, the introduction of novel transition metal agents in clinical treatment is exceptionally slow. So far, Ru(II) and Ru(III) complexes have shown very promising properties while the Ru(III) compound, [ImH][trans-Cl4(Me2SO)(Im)Ru(III)] (Im=imidazole, NAMI-A), is the first ruthenium compound that successfully entered phase I clinical trials. Rhodium belongs to the same group as platinum and ruthenium. However, rhodium compounds, analogues to the corresponding platinum and ruthenium compounds that possess significant antitumor properties, were found to be less effective as anticancer agents mainly due to their toxic effects. Dimeric mu-Acetato dimers of Rh(II) as well as monomeric square planar Rh(I) and octahedral Rh(III) complexes have shown interesting antitumor properties.

Thermotherapy in the management of choroidal melanoma

During the past 20 years of enucleation, which was the standard treatment for choroidal melanoma over more than a century, has largely been replaced by eye salvaging therapies such as radiotherapy or local resection. In 1995 transpupillary thermotherapy (TTT) using an infrared diode laser was introduced as a new conservative therapy for patients with choroidal melanoma. TTT can be defined as a heat treatment modality, which is delivered through a dilated pupil to the tumour surface. The technique uses a wide diode laser beam diameter with a low irradiance and a long exposure time. TTT induces tumour necrosis at sub-photocoagulation levels by a direct cell destructive effect with only a few ocular complications. TTT can be performed as sole therapy or combined with plaque radiotherapy, thus permitting a lower radiation dose. For amelanotic tumours dye-enhanced TTT with indocyanine green can be used. In this paper we review the role of sole or combined TTT, related to the current other treatment modalities for choroidal melanoma.

Does escalation of the apical dose change treatment outcome in beta-radiation of posterior choroidal melanomas with 106Ru plaques?

PURPOSE

To show the results of treating posterior uveal melanomas with 106Ru plaque beta-ray radiotherapy and to review and discuss the literature concerning the optimal apical dose prescription (100 vs. 160 Gy).

METHODS AND MATERIALS

Forty-eight patients with uveal melanomas (median height 3.85 mm + 1 mm sclera) were treated with ruthenium plaques. The median apical dose was 120 Gy, the median scleral dose 546 Gy.

RESULTS

After 5.8 years of follow-up, the overall 5-year survival rate was 90%, the disease specific 5-year survival rate was 92% (3 patients alive with metastasis). Six percent received a second ruthenium application, 10% of the eyes had to be enucleated. Local control was achieved in 90% of the patients with conservative therapy alone. Central or paracentral tumors showed 50% of the pretherapeutic vision after 4 years, and 80% of the vision was preserved in those with peripheral tumors. The main side effects were mostly an uncomplicated retinopathy (30%); macular degeneration or scarring led to poor central vision in 30% of cases.

CONCLUSION

Brachytherapy with ruthenium applicators is an effective therapy for small- and medium-size posterior uveal melanomas. Our results are comparable to other series. The treatment outcome does not seem to be capable of improvement by increasing the apical dose. An internationally accepted model for defining the dosage in brachytherapy is needed.

Uveal melanomas. Conservation treatment

Eye conservation can be achieved in patients with uveal melanomas by several techniques, with external beam charged particle (proton) therapy and episcleral radionuclide plaque therapy being used most commonly. The probability of visual preservation and of eye retention with either technique is related to tumor size and location. If vision is poor or absent in the fellow eye, even very large tumors can be treated with the proton beam, with a 75% to 80% probability of eye salvage and preservation of some degree of visual function. Local control is achieved in a large proportion of treated eyes with either technique probably because of the large doses that can be focally administered to these relatively small tumors with those techniques. Achieving local control may also contribute to improved survival in some patients. Survival clearly has not been compromised. Useful vision is preserved in eyes with tumors occurring in a favorable location with respect to the optic disc or macula. A dose-searching trial, aimed at improving visual outcome in patients with tumors in unfavorable locations, has been completed and has provided data to aid in designing future trials. Successfully treating uveal melanoma without removal of the involved eye is one of the major oncologic triumphs of the latter part of the 20th century. Very high rates of local control can be achieved with heavy charged particle external beam radiotherapy or 125I episcleral plaque brachytherapy, with preservation of a functionally useful eye in many patients. The excellent results in the eye melanoma patients treated with external beam proton therapy also demonstrate that almost all the patients can successfully cooperate in their treatment by voluntarily fixating the eye on a particular point during treatment, so that their tumor is positioned properly in the beam during treatment. Conservative treatment can achieve local control rates similar to or superior to those achieved with radiation therapy alone in other commonly treated solid tumors, including early stage carcinomas of the breast, vocal cord, and prostate. Continued careful follow-up of conservatively treated patients will provide even better understanding of the radiation effects on uveal melanomas and on normal ocular structures. It is also impressive that these gains have not been achieved at a cost of increased mortality: survival rates in irradiated patients are at least as good as after enucleation. Further observation will reveal whether these initial dramatic and encouraging results will be maintained. The COMS Study may provide additional data in this regard at least regarding survival after brachytherapy relative to enucleation. It will not, however, clarify indications for the two types of radiotherapy (brachytherapy and charged particle therapy) nor will it allow direct comparisons of acute and chronic ocular effects of those therapeutic modalities. The UCSF-LBL trial mentioned previously, which compared helium ion therapy with 125I episcleral plaque treatment, has documented the superiority of charged particle therapy to plaque therapy in terms of local tumor control and eye retention. Of interest is a recent survey reporting that choice of treatment for uveal melanoma did not seem to be associated with large differences in quality of life when assessed at long-term follow-up. The distant failures and metastatic deaths in uveal melanoma patients, more common with larger and more anteriorly located tumors, are most distressing. A randomized clinical trial of adjuvant systemic therapy is clearly indicated but has not been mounted because of the relatively poor results obtained with systemic therapy in metastatic melanoma patients. The recent report of improved survival in cutaneous melanoma patients at high risk for metastasis who were treated with interferon is encouraging, and it led to the initiation of the nonrandomized study described previously, which uses interferon following proton eye irradiation for patients with increased risk of metastasis. Other trials would clearly be indicated if more effective systemic therapies become available.

A linac-based stereotactic irradiation technique of uveal melanoma

PURPOSE

To describe a stereotactic irradiation technique for uveal melanomas performed at a linac, based on a non-invasive eye fixation and eye monitoring system.

METHODS

For eye immobilization a light source system is integrated in a standard stereotactic mask system in front of the healthy eye: During treatment preparation (computed tomography/magnetic resonance imaging) as well as for treatment delivery, patients are instructed to gaze at the fixation light source. A mini-video camera monitors the pupil center position of the diseased eye. For treatment planning and beam delivery standard stereotactic radiotherapy equipment is used. If the pupil center deviation from a predefined 'zero-position' exceeds 1 mm (for more than 2 s), treatment delivery is interrupted. Between 1996 and 1999 60 patients with uveal melanomas, where (i) tumor height exceeded 7 mm, or (ii) tumor height was more than 3 mm, and the central tumor distance to the optic disc and/or the macula was less than 3 mm, have been treated. A total dose of 60 or 70 Gy has been given in 5 fractions within 10 days.

RESULTS

The repositioning accuracy in the mask system is 0.47+/-0.36 mm in rostral-occipital direction, 0.75+/-0.52 mm laterally, and 1.12+/-0.96 mm in vertical direction. An eye movement analysis performed for 23 patients shows a pupil center deviation from the 'zero' position<1 mm in 91% of all cases investigated. In a theoretical analysis, pupil center deviations are correlated with GTV 'movements'. For a pupil center deviation of 1 mm (rotation of the globe of 5 degrees ) the GTV is still encompassed by the 80% isodose in 94%.

CONCLUSION

For treatments of uveal melanomas, linac-based stereotactic radiotherapy combined with a non-invasive eye immobilization and monitoring system represents a feasible, accurate and reproducible method. Besides considerable technical requirements, the complexity of the treatment technique demands an interdisciplinary team continuously dedicated to this task.

Cell proliferation activity in posterior uveal melanoma after Ru-106 brachytherapy: an EORTC ocular oncology group study

AIM

To evaluate the cell proliferation activity in posterior uveal melanomas after Ru-106 brachytherapy.

METHODS

Eyes containing choroidal or ciliary body melanoma from seven ocular oncology centres, which were enucleated after first being treated by Ru-106 brachytherapy and which had enough melanoma tissue to enable histological assessment, were included. The 57 eligible specimens were divided into a group of 44 eyes that were enucleated because of tumour regrowth, and a non-recurrent group of 13 eyes that were enucleated because of complications such as neovascular glaucoma. 46 non-irradiated eyes harbouring uveal melanoma served as a control group. All specimens underwent routine processing. They were cut into 5 microm sections, and were stained with two main cell proliferation markers: PC-10 for PCNA and MIB-1 for Ki-67. The stained sections were assessed, and the cells that were positive in the immunostaining were counted in each section. The results were evaluated by various statistical methods.

RESULTS

The PC-10 score showed a statistically significant difference across the three groups (p = 0.002). The control group showed the highest PC-10 score (median 31.0 PCC/HPF) followed by the tumour regrowth group (median 4.9 PCC/HPF). The lowest PC-10 scores were found in the non-recurrent tumours (median 0.05 PCC/HPF). The MIB-1 score in the control group (median 5.77 PCC/HPF) was similar to the regrowth group (median 5.4 PCC/HPF). In contrast, the MIB-1 score in the non-recurrent tumours was statistically significantly lower (median 0.42 PCC/HPF). The PC-10 and MIB-1 scores were similar in tumours composed of either spindle cells or epithelioid cells in all groups.

CONCLUSIONS

The non-recurrent melanomas demonstrate significantly lower cellular proliferation activity than melanomas that showed regrowth or that were not irradiated at all. In our hands, PCNA gave more meaningful information than Ki-67. Our findings strongly support the need for treating regrowing posterior uveal melanoma either by enucleation or re-treatment by brachytherapy. On the other hand, also in the non-recurrent uveal melanomas there are viable cells with potential for proliferation, although fewer in number, with unknown capacity for metastatic spread. Therefore, the irradiated tumours should be followed for many years, probably for life.